Abstract: A hitless path switching method without a bit loss. The same digital line signals on a working path and a protection path are continuously monitored independently for bit errors. If a bit error occurs in the working path and no bit error occurs in the protection path, a switching trigger is produced and a switching operation from the working path to the protection path is performed on a data block basis. Only correct data are transferred to downstream apparatuses. Reliable hitless switching is achieved not only in response to a failure in a path, but also in response to a bit error. Using data blocks of one frame length with an indicator for bit error checking placed at its beginning or top makes effective switching possible.

Abstract: A radio communication system and method employs matrix processing of received and transmitted signals to minimize co-channel interference. In one embodiment, the system and method transmits signals to a plurality of remote units by: i) correlating a signal received from a new remote unit during random access transmission with a plurality of individual antenna beam element signals to determine a new column of coefficients for a receive matrix; ii) determining a new inverse C-matrix for receiving traffic from the new remote unit based on an old inverse C-matrix and the new column; iii) transforming the new column to a new transmit C-matrix row by scaling relative coefficient phase angles using a ratio of up- to down-link frequencies; iv) determining a new transmit inverse C-matrix based on an old transmit inverse C-matrix and the new transmit C-matrix row; and v) transmitting signals to the remote units using the new transmit inverse C-matrix.

Abstract: The circuit and method for detecting data collisions in a communication network, the circuit including: a data transition detecting section for receiving Manchester encoded data signals RXD, and detecting a transition at the center of the bit cell of the encoded data signals, and outputting a transition detecting signal Z having a certain pulse width; a delayer for delaying received clock signals RXC having a certain cycle synchronized with the received data signals RXD, and outputting delayed clock signals DRXC; and a data collision detecting section turning to an active mode in accordance with a data receiving status signal CRS illustrating the receiving status of the received data signals, and shifting the status of output signals in accordance with the transition detecting signal Z upon clocking of the delayed clock signal DRXC.

Abstract: A method of detecting fractional channels in a telecommunications circuit. A non-idle data rate is measured for each channel in the telecommunications circuit. Channels having matching non-idle data rates are grouped into sets. Non-idle data rates are measured again for the channels within each set. In each set, any channels having non-matching non-idle data rates (with a small predetermined range of permissible variability) are eliminated. The measurement for each set is repeated multiple times. Each remaining set has channels that have substantially identical non-idle data rates over multiple time periods and each remaining set is assumed to constitute a fractional channel. Non-idle data rates are measured by counting non-idle octets over a fixed period of time, or by measuring throughput (non-idle octets per second) or by measuring utilization (throughput/capacity).

Abstract: Within a cell-oriented communication network, a switching equipment (CCa) located at the start of a path pair duplicates a message cell stream supplied thereto for redirection. The message cell streams resulting therefrom are separately supplied to a switching equipment (CCb) located at the end of the path pair via an active path (AP) and via an alternate path (EP) of the path pair allocated thereto. A decentralized synchronization means (SY) or, respectively, a plurality of decentralized synchronization means (SY1, SY2 or, respectively, SY3, SY4) is or, respectively, are provided therein, a synchronization of the two message cell streams ensuing therein while initially forwarding the message cell stream of the active path. After such a synchronization, only the message cell stream of the alternate path is then forwarded.

Abstract: A method and an apparatus for searching code division multiple access pilot signal energies includes limiting a pilot signal window size above a lower limit and only analyzing search result data corresponding to an instructed pilot signal window size. A central processing unit instructs a searcher receiver within a mobile station modem application specific integrated circuit to search for pilot signal energies within an instructed pilot signal search window unless the instructed pilot signal window size is smaller than a pilot signal window size lower limit. In such a case, the pilot signal search window size is artificially designated as the pilot signal window size lower limit to prevent excessive search completion interrupts from over utilizing central processing unit resources.

Abstract: In a network utilizing asynchronous transport mode (ATM) transport and/or switching, the VPI/VCI values have meaning beyond the boundaries of each individual ATM processing element. At the very least, the VPI represents a source identifier related to the provider of the particular program or service carried through the cell stream. The VPI value is maintained constant throughout the network, without translation thereof by any ATM processing element. In the preferred embodiments, the VCI also is maintained constant and serves to identify a particular service or session. For example, for each broadcast service the VCI represents a channel identifier of the program offered by the service provider identified by the associated VPI value. For an interactive session, a VCI value is assigned to the session with a particular subscriber terminal on a dynamic basis. The VCI value for such a session remains valid throughout the network for the duration of that session, without translation or reassignment.

Abstract: A novel apparatus, capable of adaptively encoding input digital audio signals from N number of channels, comprises N number of filters for filtering the input digital audio signals, respectively; a first estimator for estimating a first parameter for each of the input digital audio signals; a second estimator for estimating perceptual entropies of the respective frames for each of the input digital audio signals based on the first parameter, to thereby derive a mean and a standard deviation of a first frame group, and for generating second frame groups including F number of frames for each of the N number of channels; a first bit allocation unit for determining bits for each of the second frame groups based on the perceptual entropies for the second frame groups and mean and standard deviation parameters and for generating bit allocation information corresponding to the determined bits for the second frame groups; a second bit allocation unit for determining bits for the respective subbands of each frame incl

Abstract: A wire-free telecommunications system having a plurality of base stations and mobile elements which form a wire-free telecommunications subsystem. Each of the base stations ,and each of the mobile elements has a circuit arrangement to which is assigned a controlling program. The system has radio links at predetermined frequencies and in a plurality of time slots in time-division multiplex channels. The controlling program uses only a subset of time slots which do not follow one another directly, from a number of time slots, which are predetermined for the radio links.

Abstract: A method of automatically determining an order of transmitting a packet for a local area network using the CSMA/CD protocol. In transmitting a packet from an arbitrary station I on the local area network while another station P is transmitting a packet, the packet of the station I is automatically classified into three cases. The first, denoted by letter [A]a packet whose transmission process is not completed, is at the station I before a requested time if transmission starts after the transmission packet of the other station P is transmitted completely. The second, denoted by letter [B], is a packet whose transmission process does not completed at the station I before a requested time if transmission of another station Q is permitted after the transmission packet of the other station P is transmitted completely. The third, denoted by letter [C], is a packet which does not belong to cases [A] and [B]. A transmission process of the packet is performed in accordance with the classification result.

Abstract: A RF site link for communicating between a centralized switching system and a plurality of mobile communications RF base stations is disclosed. The RF site link includes a plurality of RF link devices connected to centralized switching equipment. The RF link devices transmit signals to and receive signals from the remote base stations over the same working channels that the base stations use to communicate with the mobile or portable radios within each of the base stations' areas of operation. A RF control link is provided to control the assignment of the working channels between the centralized switching equipment and each of the base stations within the system.

Abstract: An apparatus for setting an ID number in a station of a communication system in which a multiplexed signal including a preliminary signal and a control information signal comprising the ID number is interchanged between the adjacent stations of stations connected in series, and the stations are respectively responsive to the control information signal having the same ID number as that set in the station, for controlling the station. The apparatus provides a centralized supervisor and in the station, an ID setting circuit and a switching circuit. The centralized supervisor sends to one of the stations, a control information signal including the ID number and an ID set command. The ID setting circuit sets the ID number by storing the ID number included in the received control information signal in a memory device.

Abstract: A transmission power control method is disclosed for controlling transmission power of radio communications in a CDMA system. The transmission power of a first transmitted signal transmitted from a first station is determined by a transmission power control signal contained in a second transmitted signal sent from a second station. The first station receives the second transmitted signal in the form of convolutional codes, and decodes it by using a first Viterbi decoder and a second Viterbi decoder. The first and second Viterbi decoders includes path memories with the path history length of different first predetermined lengths. The transmission power control signal contained in the second transmitted signal is extracted from the output of the second Viterbi decoder, whereas the other information data is obtained from the output of the first Viterbi decoder. The first station controls the transmission power of the first transmitted signal on the basis of the extracted transmission power control signal.

Abstract: In a data communication system, even when cycle start data or a communication start signal of a communication cycle is not received, data blocks corresponding to that communication cycle can still be transmitted by effectively utilizing the frequency band. In the data communication system, space for at least one additional data block is allocated to every communication cycle such that the number of data blocks transmittable in a communication cycle is greater than the total number of data blocks received in that cycle, and the data blocks are transmitted in first-in-first-out order as a packet following the communication start signal.

Abstract: A pseudo or virtual LAN system is formed from point-to-point communications links and dynamic configurable nodes. In each node, commands from upper layer applications are processed in Logical Link Control sub-layer station component to generate LCC data transfer requests, which are in turn converted to Data Link Control Layer data transfer requests in a LAN simulator. DLC data transfer requests are then transferred through point-to-point communication links to other one or more nodes. Asynchronously, with the above processes, a network layer manager maintains the data on the physical formation of nodes participating in the pseudo LAN system according to connection/disconnection between the node concerned and other one or more nodes.

Abstract: Within a cell-oriented communication network (ATMN), a message cell stream supplied to a switching equipment (CCa) located at the start of a path pair is duplicated by the switching equipment in response to a request. The two message cell streams resulting therefrom are supplied to a central synchronization device (AS) allocated to the switching equipment (CCb) located at the end of the path pair, being supplied thereto separately via an active path (AP) and via an alternate path (EP) allocated thereto. In the synchronization means, a synchronization of the two message cell streams ensues, while the message cell stream of the active path is being initially forwarded. After this, only the message cell stream of the alternate path is forwarded, upon disconnection of the central synchronization means from the transmission path.

Abstract: A jitter/wander reduction mechanism monitors the ratio of pulse stuffing, to detect whenever the pulse stuffing ratio is proximate a prescribed undesirable ratio of stuffs per stuffing opportunity, which causes the wander to be a large number of unit intervals. A stuffing pulse accumulator-controlled frequency shift control circuit monitors the signal produced by a multiplexer (and demultiplexer for full duplex mode) control logic circuit and incrementally adjusts, as necessary, the frequency of a synchronized clock signal input to the multiplexer (and demultiplexer). The magnitude of the incremental frequency shift is sufficient to drive the synchronized clock away from the frequency associated with the undesired stuff ratio to a frequency that is sufficiently separated from the undesired value to produce a stuffing ratio other than the undesired value and reduce the jitter/wander.

Abstract: An apparatus and method for establishing frame synchronization in a satellite communication system which receives a modulated signal having frames, such that a unique word and data are multiplexed in each of the frames. A demodulator demodulates the modulated signal and provides a demodulated signal including the unique words. A signal detector compares the signal power of the demodulated signal with a threshold signal and provides a detection signal. A selector provides, in accordance with the detection signal, the detected demodulated signal or fixed data as a selected signal. A frame synchronizing circuit detects the unique word from the selected signal, when the demodulated signal is provided as the selected signal by the selector, and establishes frame synchronization in accordance with the detected unique word.

Abstract: A plurality of ATM layer receiving blocks to which different applications are allocated are provided for a physical layer receiving part receiving data from an ATM transmission line and carrying out prescribed physical layer processing. The plurality of ATM layer receiving blocks incorporate data from the physical layer receiving allocated thereto are supplied to execute prescribed ATM block only when data utilized by the applications layer processing, for transmitting the processed data to corresponding higher layer processing functional blocks. A plurality of ATM layer transmission blocks responsible for different applications are provided in parallel with each other and coupled to a common ATM layer transmission block for data communication between a terminal and a network data transmission line. Thus implemented is a generic interface between an ATM layer and a physical layer in a terminal-to-network interface unit in a network in which data communication is carried out in an asynchronous transfer mode.

Abstract: A telecommunications system handles 800 calls between first and second networks in different countries. In the preferred embodiment, call handling equipment of the second network receives a call from a call origin in the first network, wherein the call was placed using an 800 number corresponding to a destination in the second network and wherein the second network includes interexchange carriers and local exchange carriers. Preferably, the call is received in call handling equipment of one of the interexchange carriers and carried to the destination by the interexchange carrier to which the 800 number is assigned. In one embodiment, the call is reoriginated after receipt by the call handling equipment of a local exchange carrier which routes the call to the assigned interexchange carrier. Billing charges are assessed to the origin for international toll charges and to the destination for 800 toll charges in the second network.